A Florida investigator told FBI agents weighing possible civil rights violations against the neighborhood watch volunteer who killed teenager Trayvon Martin that he believed George Zimmerman's actions were based on Martin's attire rather than skin color, describing him as "overzealous" but a "soft guy" with a "little hero complex."

Sanford Police Department investigator Chris Serino "believes that when Zimmerman saw Martin in a hoody, Zimmerman took it upon himself to view Martin as acting suspicious," according to documents released today by the State Attorney's Office.

The documents in the case also show that in seeking to determine whether the killing of Martin can be classified as a hate crime, the FBI interviewed Zimmerman's former co-workers, friends and neighbors. One neighbor called him "culturally rounded" with no racial prejudices, as did Joe Oliver, the African-American family friend and co-worker who came to Zimmerman's defense in the initial days of the public outcry.

But the documents that include surveillance video, seven calls from Zimmerman to the Sanford Police department from April 2011 to January 2012, photos of Martin's attire after the shooting and more than 200 pages of investigator reports also show a man almost obsessively involved with patrolling his community.

The documents also shed light on Zimmerman's allegedly racist comment. In his call to Sanford Police that night, Zimmerman is heard muttering under his breath something that to many sounded like "f---ing coon." But a Sanford officer told FBI officials about the presence of several local gangs who call themselves goons.

The public also sees, for the first time, Martin's now iconic hoodie, as well as the sweatshirt he wore underneath. The bullet hole is clearly visible, encircled by a bloodstain.

Zimmerman reached out to police in 2011 to set up the neighborhood watch program. The Homeowner's Association had asked Zimmerman to be the coordinator and he was handed a handbook and was explained the duties and responsibilities to which he and other coordinators should adhere, according to the documents.

In calls made to the Sanford Police Department in 2011 and early 2012, the criminal justice major can be heard complaining about a spate of burglaries in the community. He also alerted the police of minor occurrences, including one call that informed police that a neighbor had left their "garage door open."

In a statement provided by Zimmerman's ex-fiancée, she told police that Zimmerman hit her in the mouth for chewing gum, and that a few weeks later there was an incident in which Zimmerman refused to leave her house and, she said, lied to police about a scratch he had incurred from the dog, saying that she instead scratched him. The couple were engaged for a year before calling it off.

She noted Zimmerman had aspired to become a police officer and that while he had a temper, she did not consider him to be the kind of person to put himself in harm's way.

The documents also go into detail about an incident in 2005 in Orange County involving Zimmerman and off-duty officers that resulted in his allegedly shoving one of them and displaying "an angry demeanor" even after the officers identified themselves. He was promptly arrested but charges were never filed.

As for Martin, the new evidence paints a clearer picture of the final days of his life. In the day before he was killed, he accompanied his cousin to a football game. His father later gave him a few dollars to go to the movies but he never went. The next morning, Martin and his cousin, who says they spent time together almost every weekend, went to a convenience store and that was the last they saw each other.

When the cousin was later approached by investigators about who was screaming in 911 audio recordings the night of the shooting, he said he could swear "on a stack of Bibles that it was Trayvon."

The girlfriend of Martin's father told investigators that this was the first time the teen had stayed at her Sanford home without his dad. Martin's father was attending a convention nearby. On the night of the teen's murder, Martin's father took his girlfriend of 2 ½ years to the dinner.

When they came home, there was no sign of Martin. She told investigators that it was probably the first time the teen had walked to the nearby convenience store.